Washington (CNN) -- After months of criss-crossing the country and trying to woo potential supporters in early voting states, seven Republicans hoping to capture their party's presidential nomination will meet this month for the first New Hampshire debate of the 2012 election.

This is the first time that Bachmann, Gingrich and Romney will appear in a 2012 presidential debate. The event is being sponsored by CNN, WMUR and the New Hampshire Union Leader. CNN Chief National Correspondent/Anchor John King will moderate the debate with journalists from WMUR and the Union Leader participating in the questioning.

The debate takes place eight months before the New Hampshire primary, a critical contest on the road to the Republican presidential nomination. The debate will air live from 8 p.m. to 10 p.m. ET in New Hampshire and across the country.

The three media partners created objective criteria to determine who would participate in the debate. The participants needed to achieve a minimum threshold in either national or New Hampshire primary polls. The full criteria can be found here.

Invitations were extended to the seven Republicans who will appear on stage in New Hampshire as well as Indiana Gov. Mitch Daniels, former New York Mayor Rudy Giuliani, former Arkansas Gov. Mike Huckabee, former Utah Gov. Jon Huntsman, former Alaska Gov. Sarah Palin and businessman Donald Trump.

In recent weeks, Daniels, Huckabee and Trump all publicly said they would not seek the Republican presidential nomination. Giuliani declined the debate invitation, as did Huntsman.

Several months before the last New Hampshire presidential primary, CNN, WMUR and the Union Leader hosted debates at Saint Anselm in 2007 -- events that helped introduce the Republican and Democratic candidates to voters in the state and around the nation.